Came across this product after following the company's well-executed Facebook campaign. Leadquizzes makes it fairly easy to build/launch/embed quizzes that qualify prospects and build your email list.
I've talked to a few info-product marketers who've used quizzes to get email signups from Facebook for as little as $0.26 cents per lead. It needs a lot more integrations with email marketing software (or an integration with Zapier), but this looks super promising.
Blockbutler
Blockbutler
Roundups
Appcues